From d982dbb620b6a5d9992b3259550c3e16e7e8e28a Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Wed, 23 Jul 2014 11:16:44 -0400 Subject: [PATCH 2/6] Extend dsm API with a new function dsm_unkeep_mapping. This reassociates a dynamic shared memory handle previous passed to dsm_keep_mapping with the current resource owner, so that it will be cleaned up at the end of the current query. --- src/backend/storage/ipc/dsm.c | 18 ++++++++++++++++++ src/include/storage/dsm.h | 1 + 2 files changed, 19 insertions(+) diff --git a/src/backend/storage/ipc/dsm.c b/src/backend/storage/ipc/dsm.c index a5c0084..6039beb 100644 --- a/src/backend/storage/ipc/dsm.c +++ b/src/backend/storage/ipc/dsm.c @@ -796,6 +796,24 @@ dsm_keep_mapping(dsm_segment *seg) } /* + * Arrange to remove a dynamic shared memory mapping at cleanup time. + * + * dsm_keep_mapping() can be used to preserve a mapping for the entire + * lifetime of a process; this function reverses that decision, making + * the segment owned by the current resource owner. This may be useful + * just before performing some operation that will invalidate the segment + * for future use by this backend. + */ +void +dsm_unkeep_mapping(dsm_segment *seg) +{ + Assert(seg->resowner == NULL); + ResourceOwnerEnlargeDSMs(CurrentResourceOwner); + seg->resowner = CurrentResourceOwner; + ResourceOwnerRememberDSM(seg->resowner, seg); +} + +/* * Keep a dynamic shared memory segment until postmaster shutdown. * * This function should not be called more than once per segment; diff --git a/src/include/storage/dsm.h b/src/include/storage/dsm.h index 1d0110d..1694409 100644 --- a/src/include/storage/dsm.h +++ b/src/include/storage/dsm.h @@ -37,6 +37,7 @@ extern void dsm_detach(dsm_segment *seg); /* Resource management functions. */ extern void dsm_keep_mapping(dsm_segment *seg); +extern void dsm_unkeep_mapping(dsm_segment *seg); extern void dsm_keep_segment(dsm_segment *seg); extern dsm_segment *dsm_find_mapping(dsm_handle h); -- 1.7.9.6 (Apple Git-31.1)